Spherical inorganic particles having surface bumps formed thereon, and method of manufacturing same

Abstract

The inorganic particle according to the present invention is composed of aggregation of crystalline and amorphous small particles and has a spherical and smooth surface. The spherical appearance, low crystallinity and narrow particle size distribution of inorganic particle are more advantageous in reducing scratch defects in the CMP process. In addition, since the small particles on the surface of the inorganic particle provide more active sites, the inorganic particle has an excellent removal rate, so it is advantageous as a next-generation CMP abrasive.

The invention claimed is: 
     
       1. An inorganic particle formed by aggregation of a plurality of small particles, wherein the small particle has a mixed phase of a crystalline phase and an amorphous phase and has a degree of crystallinity of 90% or less, wherein the small particle has a particle diameter of 10 nm or less, wherein the inorganic particle is CeO 2  particle, and wherein the ratio of Ce 3+ /Ce 4+ is 40 to 60. 
     
     
       2. The inorganic particle according to  claim 1 , wherein the inorganic particle has a density of 3.0 to 5.0 g/ml, an average particle diameter of 30 to 1000 nm, and a standard deviation of the particle diameter of 20 or less. 
     
     
       3. The inorganic particle according to  claim 1 , wherein the inorganic particle has an isoelectric point of pH 5 to 7. 
     
     
       4. The inorganic particle according to  claim 1 , wherein the inorganic particle has a zeta potential of +30 to +50 mV or −30 to −50 mV in an aqueous dispersion of pH 4. 
     
     
       5. A method of manufacturing the inorganic particle of  claim 1 , comprising:
 (a) dissolving a self-assembling surfactant in a solvent; 
 (b) dissolving or dispersing an inorganic precursor in the solvent before, after, or simultaneously with the step (a) to prepare an inorganic precursor solution; and 
 (c) forming small particles having a mixed phase of a crystalline phase and an amorphous phase in the shell formed by the surfactant through the self-assembly reaction of the inorganic precursor and the surfactant, and then forming an inorganic particle by aggregation of a plurality of the small particles. 
 
     
     
       6. The method of manufacturing the inorganic particle according  claim 5 , wherein the method further comprises treating the inorganic particle obtained in the step (c) with an acid and a base to obtain the inorganic particle having a controlled surface charge. 
     
     
       7. The method of manufacturing the inorganic particle according  claim 5 , wherein the self-assembling surfactant is at least one selected from a cationic surfactant, an anionic surfactant and an amphoteric surfactant having a charge capable of ionically bonding with the inorganic precursor, which has a functional group that allows a condensation reaction or crosslinking reaction. 
     
     
       8. The method of manufacturing the inorganic particle according  claim 7 , wherein the functional group that allows a condensation reaction or crosslinking reaction is at least one selected from the group consisting of an amide group, a nitro group, an aldehyde group, and a carbonyl group. 
     
     
       9. The method of manufacturing the inorganic particle according  claim 5 , wherein the self-assembling surfactant has a structure of the following formula 1 
       
         
           
           
               
               
           
         
         wherein R 1  and R 3  are independently a hydrogen atom, a C 1 -C 10  alkyl group or a C1-C10 alkoxy group, R 2  is a substituent of formula 2 below, and n is 2 or more, 
       
       
         
           
           
               
               
           
         
         wherein R 4  and R 5  are independently a hydrogen atom, a C 1 -C 10  alkyl group or a C 1 -C 10  alkoxy group, R 6  is a C 1 -C 10  alkylene group or a single covalent bond, and * represents a connection site. 
       
     
     
       10. The method of manufacturing the inorganic particle according  claim 5 , wherein the solvent is water or a mixed solvent of water and a solvent having compatibility with water. 
     
     
       11. An aqueous dispersion in which the inorganic particles of  claim 1  are dispersed in water. 
     
     
       12. The aqueous dispersion according  claim 11 , wherein the aqueous dispersion is a slurry for CMP.